As surgical knowledge and techniques have progressed, there has been a corresponding trend toward size reduction of surgical incisions and invasive instruments, thus decreasing patient trauma and contributing to rapidity of patient recovery. This has led to the practice of laparoscopic and other surgical procedures using small medical electrodes. The incidence of AIDS and other highly dangerous or fatal communicable diseases has highlighted the importance of using either discardable components or of thoroughly sterilizing those that are used more than once. While thorough sterilization may be more economical and cost effective for certain types of implements, there are others in which the harsh environments of sterilization (e.g., steam, autoclaving) may be excessively harmful or result in a reduction in useful life. Moreover, for some implements, repeated use itself may result in wear or deterioration.
In protecting against communication of disease, a variety of electrosurgical techniques and implements have heretofore been proposed, illustrative of which are those described in U.S. Pat. No. 1,916,722 granted to F. M. Ende Jul. 4, 1933; German Patent 2,404,764 granted to Bernard Weissman, et al. 19 Sep., 1974; PCT International Application U.S. Ser. No. 82/0084 filed by William S. Walker 25 Jan., 1982; and PCT International Application U.S. Ser. No. 91/05520 filed by Edwin Langberg 2 Aug., 1991. According to proposals of these patents, multi-element implements have included reusable bodies with removable and disposable tips or electrodes. The main bodies or holders may be sterilized if needed and re-used, and the tips, blades or electrodes either discarded after one use or sterilized and re-used. However, there remain problems such as costs and time associated with sterilization and with optimization of use of the parts that make up an assembled instrument. For example, according to prior art proposals, the minimum expected useful life of an electrosurgical instrument has been identified and records kept of the length and type of use as well as the number of times the instrument has been sterilized, thus consuming time required to keep such records. Obviously, such procedures produce undesired overhead expense. In addition, where such an instrument is discarded after the expected minimum useful life has occurred, unless it is at the lower end of the "bell curve" of life expectancy, its remaining useful life, as well as the remaining useful lives of others of the instruments is not utilized, thus foreclosing use of remaining life of each individual instrument and leading to additional inefficiencies. Accordingly, there has continued to be a need for an improved electrosurgical instrument which includes an inexpensive and dependable way of identifying individual wear or deterioration so as to permit optimum use of each individual instrument while identifying a point beyond which use should be discontinued and the main body or holder replaced.